Investigation of blood flow parameters in the microvasculature in adolescents football teams during the training process

The limiting role of the cardiovascular system when performing sports loads is associated not only with central hemodynamics, but peripheral mechanisms, regulating blood flow. One of the indicators playing a significant role is a velocity of capillary blood flow. Using the method of high-frequency ultrasound dopplerography, the study of blood flow characteristics in a microvasculature at rest and after exercise session was conducted in 53 adolescents at the age of 9-15 years with different sport experience. During these studies it was found that background blood flow velocity values in the arteriolar and capillary bed (p≤0.05) are higher, and vascular tone is lower in adolescents of 14-15 years and adolescents having a longer sport experience, compared with adolescents of 9-13 years. Blood flow indicators in a microvasculature of the older age group are closer to the values recorded in adults. Various mechanisms aimed at maintenance of muscle oxygenation during exercise, are revealed after exercise session. It is confirmed visually (on the dopplerogram) and quantitatively that mechanisms increasing blood flow to muscles are activated at less-trained adolescents (9-13 years old) during exercise. More efficient mechanisms are observed at the older age group: redistribution of blood flow and increase in number of functioning capillaries.